Solder paste is a paste-like chemical substance that plays two main roles in the soldering process: “removing oxides” and “reducing surface tension of the soldered material.” The functional components of solder paste include the matrix, flux, and surfactant.
The matrix is the main component of the solder paste, controlling its melting point. Once melted, it covers the surface of the solder joint, isolating it from the air. Additionally, it serves as a solvent for other functional components.
The flux removes, breaks, or loosens the surface oxide film of the base material through physical and chemical processes, allowing the molten solder to wet the fresh surface of the base material.
The surfactant further reduces the interfacial tension between the molten solder and the base material, facilitating better spreading of the molten solder on the surface of the base material.
The main functions of solder paste are as follows:
- Removing oxides from the surface of the base material and liquid solder during the soldering process, creating conditions for the spread of the liquid solder.
- Acting as a protective layer by covering the surface of the base material and solder with a liquid thin layer, isolating them from the air.
- Serving as a surfactant to improve the wetting and spreading properties of the liquid solder on the surface of the base material.
